你可以试试

member.substr(member.length-2);

你可以给.slice()传递一个负索引。这将指示从集合的末尾开始的偏移量。

var member = "my name is Mate";

var last2 = member.slice(-2);

alert(last2); // "te"

下面的例子使用了带有负索引的slice()

Var STR = '我的名字是maanu.'; console.log (str.slice (3));//返回'nu。“最后两个” console.log (str。片(7));//返回'name is' console.log (str。片(0,1));//返回'my name is maanu'

Slice可以用来查找子字符串。当我们知道索引时，我们可以使用另一种解决方案，如索引明智加法器。两人执行死刑的时间大致相同。

const primitiveStringMember = "my name is Mate"; const objectStringMember = new String("my name is Mate"); console.log(typeof primitiveStringMember);//string console.log(typeof objectStringMember);//object /* However when we use . operator to string primitive type, JS will wrap up the string with object. That's why we can use the methods String object type for the primitive type string. */ //Slice method const t0 = performance.now(); slicedString = primitiveStringMember.slice(-2);//te const t1 = performance.now(); console.log(`Call to do slice took ${t1 - t0} milliseconds.`); //index vise adder method const t2 = performance.now(); length = primitiveStringMember.length neededString = primitiveStringMember[length-2]+primitiveStringMember[length-1];//te const t3 = performance.now(); console.log(`Call to do index adder took ${t3 - t2} milliseconds.`);

你可以试试

member.substr(member.length-2);

尝试一下，注意你不需要在子字符串中指定结束索引。

var characters = member.substr(member.length -2);